Screen input type display device

ABSTRACT

The task of the present invention is to provide a highly reliable screen input type display device using a touch panel which can facilitate the control of a gap formed between upper and lower substrates and can stabilize the linearity of the resistance value detection of a resistance film whereby an erroneous operation of the coordinates detection can be eliminated. To solve such a task, a tape-like conductive pressure sensitive adhesive member which is formed by sandwiching a metal foil with conductive pressure sensitive adhesive material is used at a connection portion between an upper wiring electrode mounted on an upper resistance film formed on an upper substrate and an inter-substrate connection wiring electrode formed on a lower substrate.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a screen input type displaydevice having a constitution in which a touch panel which detects inputcoordinates based on the change of resistance by a push manipulation islaminated.

[0003] 2. Description of the Related Art

[0004] As an example of a display device, a liquid crystal displaydevice which is used as display means of a personal computer or as othermonitor is known. This display device irradiates illumination light toimages formed on a liquid crystal panel and visualizes the images byirradiating a transmitting light or a reflection light to a displaysurface side.

[0005] In general, a screen input type display device which adopts thistype of liquid crystal display device uses a liquid crystal panel whichsandwiches a liquid crystal layer in a space defined between a pair oflaminated substrates having pixel selecting electrodes and the like andcan generate images by changing the orientation state of liquid crystalmolecules corresponding to selected pixel portions. Since the generatedimage per se is not in the visible state, the liquid crystal panel isirradiated by giving light from outside and a transmitting light or areflection light therefrom is observed.

[0006] Recently, an information terminal which uses this type of liquidcrystal display device as display means and is provided with a touchpanel which is laminated on a screen of the liquid crystal displaydevice and inputs various information through the screen by a pushmanipulation has been widely used.

[0007] Although there exist touch panels of various systems depending onoperation principles, the most popular touch panel is one which adopts asystem in which input coordinates are detected depending on a changequantity of resistance, a so-called “analogue resistance film system”.

[0008] In this touch panel of this analogue resistance film system, onesubstrate which becomes an information input side is constituted of asoft film such as a transparent plastic sheet or the like, the othersubstrate is constituted of a transparent hard plate preferably made ofglass, and resistance films are respectively provided to opposingsurfaces of two transparent substrates. Due to such a constitution, atwo dimensional coordinates value is detected based on the resistancevalue between resistance films of respective substrates which arebrought into contact with each other with the push manipulation appliedfrom one substrate side and an output terminal.

[0009]FIG. 18 is a schematic cross-sectional view for explaining anexample of an overall constitution of a screen input type display devicewhich constitutes a display device provided with a touch panel. Thisdisplay device is constituted by laminating a touch panel 100 on aliquid crystal panel 300. Although the illustrated display device is ofa type which inserts an auxiliary light source device 200 between theliquid crystal panel 300 and the touch panel 100, a display device whichmounts the auxiliary light source device on a side opposite to a displayscreen of the liquid crystal panel 300 or a display device which is notprovided with the auxiliary light source device has been commercialized.In the drawing, numeral 202 indicates a lamp which constitutes theauxiliary light source device 200 and numeral 203 indicates a lampreflection sheet which also constitutes the auxiliary light sourcedevice 200.

[0010]FIG. 19A and FIG. 19B are schematic cross-sectional views forexplaining the constitution and the state at the time of pushmanipulation of an essential part of a signal input side of the touchpanel shown in FIG. 18. Although the upper substrate is referred as afirst substrate and the lower substrate is referred as a secondsubstrate for facilitating the explanation, these substrates may bearranged up side down.

[0011] In FIG. 19A and FIG. 19B, numeral 2 indicates an upper substratemade of a transparent film such as plastic or the like and numeral 3indicates a lower substrate made of a hard plate such as a glass plate.On inner surfaces of these two substrates 2, 3, an upper resistance film4 and a lower resistance film 5 which are respectively preferably madeof ITO are formed as a coating. Further, in an input region AR of thelower resistance film 5 which is formed on the lower substrate 3,dot-like spacers 9 which prevent upper and lower resistance films 4, 5from coming into contact with each other in the non-input manipulationstate are formed. The spacers 9 are formed by printing using a maskhaving given apertures or a photolithography technique or the like of aphotosensitive resin.

[0012] In an adhesion region (seal region) SL which is located at anoutermost periphery of the touch panel, the upper resistance film 4 iselectrically connected to an upper wiring electrode 6 which is formed onthe upper resistance film of the upper substrate and an inter-substrateconnection wiring electrode 7 which is formed on the lower substrate.The inter-substrate connection wiring electrode 7 is connected to acoordinates recognition circuit disposed outside by a outgoing line(generally, a flexible printed circuit board: FPC) not shown in thedrawing by way of a pull-around wiring not shown in the drawing. Thelower resistance film 5 which is formed on the lower substrate 3 isconnected to a lower wiring electrode not shown in the drawing and thelower resistance film 5 is connected to the outgoing line by way of apull-around wiring not shown in the drawing which is formed on the innersurface of the lower substrate 3.

[0013] The upper wiring electrode 6 and the inter-substrate connectionwiring electrode 7 are respectively coated with protective films(insulation films) 12A, 12B and these protective films are adhered toeach other by means of a seal agent (adhesive agent or adhesive sheet)13.

[0014] In the inside of the seal region SL, the input region AR ispositioned by way of an inoperable region NR. The inoperable region NRis a portion which becomes insensitive at the time of performing thepush input manipulation. As shown in FIG. 19B, this inoperable region NRcorresponds to an input invalidation space which is formed when theupper substrate 2 is deflected toward the lower substrate 3 uponreceiving the press pressure of a nib 56 which constitutes input means.

[0015] In general, in this inoperable region NR, an inoperable regionforming member 14 is provided to prevent an input failure of informationby the push input manipulation of the nib 56. That is, the inoperableregion forming member 14 having a size which ensures the entrance of thenib 56 in the input region AR in the state shown in FIG. 19B and is madeof transparent insulation material is provided to the inoperable regionNR.

[0016]FIG. 20 is a schematic cross-sectional view for explaining theconstitution of an essential part of a connection portion between theupper wiring electrode 6 and the inter-substrate connection wiringelectrode 7 of the touch panel. The upper wiring electrode 6 formed onthe upper resistance film 4 on the inner surface of the upper substrate2 and the inter-substrate connection wiring electrode 7 formed on theinner surface of the lower substrate 3 are electrically connected witheach other by way of an adhesive agent 14 made of epoxy resin in whichmetal particles are mixed.

[0017] In the conventional screen input type display device providedwith the touch panel having such a constitution, conductive thin filmsmade of silver paste or the like which are coated on the upper and lowerwiring connection portions and the adhesive agent in which the metalparticles are mixed are used and hence, when a gap between the upper andlower substrates is set to approximately 40 μm to 150 μm, it isdifficult to control such a gap. When the gap between the upper andlower substrates is not uniform, a user has a discomfort in his inputfeeling at the time of performing the push manipulation. This has beenone of tasks to be solved by the present invention.

[0018] Further, since the adhesive agent 14 in which the metal particlesare mixed is used for the connection between the upper wiring electrode6 formed on the upper resistance film 4 of the upper substrate 2 and theinter-substrate connection wiring electrode 7 formed on the lowersubstrate 3, the irregularities are liable to be generated in theconnection resistance and it is difficult to stabilize the linearity ofthe detected resistance value. This brings about an erroneous operation.To reduce this erroneous operation, the load which a coordinatesdetection circuit must bear becomes large. This also has been a task tobe solved for enhancing the reliability of the screen input type displaydevice.

SUMMARY OF THE INVENTION

[0019] Accordingly, it is an object of the present invention to providea screen input type display device using a touch panel having a highreliability which can solve the above-mentioned tasks the prior art, caneasily perform a gap control between an upper and lower substrates, canstabilize the linearity of the resistance value detection with the useof the resistance films and can eliminate the erroneous operation of thecoordinates detection.

[0020] To achieve the above-mentioned object, for establishing theconnection between a wiring electrode connected to a resistance film ofa first substrate and an inter-substrate connection wiring electrodeformed on a second substrate, the present invention adopts a planar (ortape-like) structural body which sandwiches a metal foil betweenconductive pressure sensitive adhesive agents, that is, a conductivepressure sensitive adhesive member which coats the conductive pressuresensitive adhesive agents on both surfaces of the metal foil. Theresistance film of the first substrate may be directly brought intocontact with the conductive pressure sensitive adhesive member withoutinterposing a wiring electrode therebetween.

[0021] Further, as conductive material contained in the conductivepressure sensitive adhesive agent, metal particles preferably made ofcopper particles or alternatively plastic particles or glass particleswhich have a metal plating made of nickel, gold or other metal formed onsurface thereof can be used.

[0022] With the use of the structural body having such a constitution,since the resistance film of a first substrate or the wiring electrodewhich is connected to the resistance film and the inter-substrate wiringelectrode formed on the second substrate are electrically connected by aface contact, the stability of the contact resistance is achieved.Accordingly, the linearity of the resistance value detection is improvedso that the erroneous operation of the coordinates detection can beobviated and a load that a coordinates detection circuit must bear canbe reduced.

[0023] Further, according to the constitution of the present invention,by changing a thickness of the metal foil, the gap between the firstsubstrate and the second substrate (upper and lower substrates) can bearbitrarily, accurately and uniformly controlled, and the input feelingcan be enhanced.

[0024] The present invention adopts a structural body (conductivepressure sensitive adhesive member) which is formed by coating pressuresensitive adhesive material in which metal particles are mixed on onesurface of a metal foil and coating pressure sensitive adhesive materialin which conductive particles formed by applying a metal plating onsurfaces of plastic particles or conductive particles formed by applyinga conductive metal plating on surfaces of glass particles are mixed onthe other surface of the metal foil.

[0025] Then, the above-mentioned one surface is made to face the firstsubstrate in an opposed manner and the other surface is made to face thesecond substrate in an opposed manner. Due to such a constitution, bymaking use of collapsing or embedding of the conductive particles, thedirect contact area between the conductive particles and the conductivepressure sensitive adhesive members formed on the inner surface ofeither one or the other substrate or between the conductive particlesand the resistance films can be increased. Here, the formation of thewiring electrode on the first substrate side can be omitted. Further, bydirectly embedding the conductive particles into the wiring electrode orthe resistance film formed on the inner surface of one substrate, thedirect contact area can be increased and the gap can be accurately set.

[0026] The above-mentioned one substrate and the other substraterespectively constitute the first substrate and the second substrate andeither one of these substrates constitutes an input-side substrate, thatis, an upper substrate of a touch panel which becomes a product or asubstrate opposite to the input-side substrate, that is, a lowersubstrate of the touch panel.

[0027] As a display device used as a screen input type display deviceaccording to the present invention, a liquid crystal display devicewhich uses a liquid crystal panel of a so-called “passive matrix type”,“active matrix type” or other known type can be used. Further, thepresent invention is not limited to the reflection-type liquid crystaldisplay device and is applicable to a transparent-type or asemitransparent/reflection type liquid crystal display device. Further,the present invention is not limited to the liquid crystal displaydevice and is applicable to other display devices.

[0028] The constitution of the screen input type display device of thepresent invention which laminates the touch panel is not limited to theconstitution described in “what is claimed is” and the constitutions ofembodiments which will be explained later. That is, the constitution ofthe screen input type display device of the present invention is alsoapplicable to any conductive connection between a first substrate and asecond substrate of a touch panel of a system which detects coordinatesbased on the change of capacity between the first and second substratesor change of other electric quantity or of a digital system. In thismanner, various modifications are conceivable without departing from thetechnical concept of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0029]FIG. 1 is an developed perspective view for explaining the entireconstitution of a first embodiment of a touch panel which constitutes ascreen input type display device according to the present invention;

[0030]FIG. 2 is a cross-sectional view taken along a line A-A of FIG. 1;

[0031]FIG. 3 is a schematic cross-sectional view for explaining a firstexample of conductive pressure sensitive adhesive member formed in aseal region of the first embodiment of the present invention;

[0032]FIG. 4 is a schematic cross-sectional view for explaining a thirdexample of conductive pressure sensitive adhesive member formed in aseal region of the first embodiment of the present invention;

[0033]FIG. 5 is a developed perspective view for explaining the entireconstitution of a second embodiment of a touch panel which constitutes ascreen input type display device according to the present invention;

[0034]FIG. 6 is a schematic cross-sectional view of an essential parttaken along a line B-B of FIG. 5 for explaining the constitution of aseal region of the second embodiment of the present invention in anenlarged form;

[0035]FIG. 7 is a cross-sectional view for schematically explaining thestructure of a first example of a conductive pressure sensitive adhesivemember in FIG. 6;

[0036]FIG. 8 is a cross-sectional view for schematically explaining thestructure of a second example of a conductive pressure sensitiveadhesive member in FIG. 6;

[0037]FIG. 9 is a cross-sectional view for schematically explaining thestructure of a third example of a conductive pressure sensitive adhesivemember in FIG. 6;

[0038]FIG. 10 is a schematic cross-sectional view for explaining theconstitution of an essential part of a third embodiment of the touchpanel constituting the screen input type display device of the presentinvention;

[0039]FIG. 11 is a schematic cross-sectional view similar to that ofFIG. 6 for explaining the constitution of a conductive pressuresensitive adhesive member of a fourth embodiment of the touch panelconstituting the screen input type display device of the presentinvention;

[0040]FIG. 12 is an explanatory view for explaining the manufacturingsteps of a touch panel used in the screen input type display device ofthe present invention;

[0041]FIG. 13 is a cross-sectional view for explaining one mode forcarrying out a screen input type display device of the presentinvention;

[0042]FIG. 14 is a cross-sectional view for explaining other mode forcarrying out a screen input type display device of the presentinvention;

[0043]FIG. 15A-FIG. 15E are views of an outer appearance of the screeninput type display device of the present invention as viewed from fivedirections;

[0044]FIG. 16A-FIG. 16D are cross-sectional views of an essential partof FIG. 15A-FIG. 15E;

[0045]FIG. 17 is an explanatory view of one example of an informationprocessing device which uses the screen input type display device of thepresent invention;

[0046]FIG. 18 is a schematic cross-sectional view for explaining aschematic constitutional example of a screen input type display devicewhich constitutes a display device having a touch panel;

[0047]FIG. 19A and FIG. 19B are schematic cross-sectional views forexplaining the constitution of an essential part of a signal output sideof the touch panel shown in FIG. 18 and the state of the touch panel atthe time of performing the push manipulation;

[0048]FIG. 20 is a schematic cross-sectional view for explaining theconstitution of an essential part of an upper and lower wiringconnection portion of the touch panel shown in FIG. 19A and FIG. 19B.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0049] The modes for carrying out the invention are explained in detailhereinafter in conjunction with embodiments where an analogue type touchpanel which detects the change of resistance is described as an example.

[0050]FIG. 1 is a developed view showing an entire constitution of afirst embodiment of a touch panel which constitutes a screen input typedisplay device of the present invention. Further, FIG. 2 is across-sectional view taken along a line A-A of FIG. 1.

[0051] On inner surfaces of a first substrate 2 (hereinafter called“upper substrate”) made of polyethylene telephthalate (PET) film and asecond substrate (hereinafter called “lower substrate”) 3 made of glass,a first resistance film (hereinafter called “upper resist film”) 4 madeof ITO (Indium Tin Oxide) and a second resistance film (hereinaftercalled “lower resistance film”) 5 are respectively formed as a coating.

[0052] In an input region AR of a lower resistance film 5 formed on thelower substrate 3, dot-like spacers 9 which prevent the upper and lowerresistance films 4, 5 from coming into contact with each other in anon-input manipulation state (ordinary state) are formed. These spacers9 are formed by printing using a mask having given apertures or by aphotolithography technique using a photosensitive resin or the like. Thearrangement interval of the spacers 9 is set greater than the width of anib which constitutes press means.

[0053] The upper resistance film 4 is electrically connected to an upperwiring electrode 6 which is formed by printing or the like in a sealregion SL and is preferably made of a silver paste, while the upperwiring electrode 6 is electrically connected to an inter-substrateconnection wiring electrode 7 through a conductive pressure sensitiveadhesive member 8. This inter-substrate connection wiring electrode 7 ispulled around by means of an inter-substrate connection wiring electrodepull-around wiring 17 formed on the lower substrate 3 to a side (outputside) where an FPC 11 is adhered with pressure and is connected to acoordinates recognition circuit disposed outside through an outgoingline carried by the FPC 11.

[0054] In the seal region disposed at a side opposite to the side(output side) where the FPC 11 is formed, the conductive pressuresensitive adhesive member 8 is interposed between the upper wiringelectrode 6 and the inter-substrate connection wiring electrode 7 sothat the upper wiring electrode 6 and the inter-substrate connectionwiring electrode 7 are electrically connected with each other bybridging and the upper and lower substrates are adhered to each other.

[0055] On the other hand, lower wiring electrodes 16 are respectivelyprovided to both end portions of the lower resistance film 5 formed onthe inner surface of the lower substrate 3 and are respectively pulledaround toward the output side through lower wiring electrode pull-aroundwiring 18. The upper resistance film 4 is formed such that the film 4terminates in front of positions where the upper resistance film 4 andthe lower wiring electrodes 16 are superposed. Accordingly, they areelectrically insulated from each other.

[0056]FIG. 3 is a schematic cross-sectional view for explaining a firstexample of the conductive pressure sensitive adhesive member provided tothe seal region in the first embodiment of the present invention. Thisconductive pressure sensitive adhesive member 8 is formed by coatingpressure sensitive adhesive material 8B in which conductive particles 8Care mixed on both surfaces of a metal foil 8A. Although a low-resistancemetal such as a copper foil, aluminum foil or the like can be used asthe metal foil 8A, the copper foil is used in this embodiment. Here, itis needless to say that a non-metallic good conductor can be used.

[0057] Although organic material made of acrylic-based material or thelike or rubber-based material can be used as the pressure sensitiveadhesive material 8B, the acrylic resin is used in this embodiment.Further, although the copper foil is used as the metal foil 8A in thisembodiment, the similar advantageous effect can be obtained with the useof the aluminum foil. Further, as the conductive particles 8C which aremixed into the pressure sensitive adhesive material 8B, any one ofparticles made of copper, aluminum, nickel, or stainless steel can beused. In this embodiment, copper particles are used. The same goes forfollowing embodiments.

[0058] According to this embodiment, the electric connection between theconductive particles 8C and the upper wiring electrode 6, theinter-substrate connection wiring electrode 7 and the metal foil 8A canbe improved and the uniformity of the gap is ensured. In theconventional touch panel, since the above-mentioned lamination isperformed by adhesion, when the displacement occurs between the upperwiring electrode 6 and the inter-substrate connection wiring electrode 7due to an application of an external force, it is difficult to returnthem to an original position. However, according to this embodiment,since means which laminates the first and second substrates whileensuring the electric connection between them is the pressure sensitiveadhesion by the conductive pressure sensitive adhesive member 8, when anexternal force is applied to displace one of two substrates made of theupper and lower substrates from the other, this displacement is allowedto make the both substrates displaced from each other and the electricconnection between the upper wiring electrode 6 and the inter-substrateconnection wiring electrode 7 is maintained while they are held in thedisplaced condition. Then, when the external force is removed, the upperwiring electrode 6 and the inter-substrate connection wiring electrode 7are made to return to the original position.

[0059] Further, in a second example of the present embodiment, as theconductive particles 8C shown in FIG. 3, conductive particles which areformed by applying a metal plating made of nickel or gold on surfaces ofhard plastic particles preferably made of PET (polyethylenetelephthalate) are used.

[0060] When the conductive particles which are formed by applying themetal plating on surfaces of the plastic particles are used, at the timeof laminating the upper substrate which constitutes the first substrateand the lower substrate which constitutes the second substrate andforming a gap between these substrates, the plastic particles arecollapsed due to the press force at the time of forming the gap.Accordingly, the contact areas of the conductive particles to the upperwiring electrode 6, the inter-substrate connection wiring electrode 7and the metal foil 8A are increased and hence, the irregularities of theresistance values are reduced whereby an advantageous effect that thelinearity of the resistance value detection can be made stable isobtained. Simultaneously, the allowance of the displacement of the upperwiring electrode 6, the inter-substrate connection wiring electrode 7due to the external force and the return of the upper wiring electrode6, the inter-substrate connection wiring electrode 7 to the originalposition can be obtained as in the case of the first example.

[0061]FIG. 4 is a schematic cross-sectional view for explaining a thirdexample of the conductive pressure sensitive adhesive member formed inthe seal region of the first embodiment of the present invention. Withrespect to this conductive pressure sensitive adhesive member 8,large-diameter conductive particles 8E are embedded in the pressuresensitive adhesive material 8D and these large-diameter conductiveparticles 8E control the gap defined between the upper and lowersubstrates in place of the metal foil in the above-mentioned example. Asthe conductive particles 8E, conductive particles which are made ofmetal particles such as copper particles or the like are formed byapplying a metal plating made of gold, nickel or the like aroundlarge-diameter plastic particles and those used in the above-mentionedexample can be used in the same manner.

[0062] When the large-diameter metal particles are used, the metalparticles are embedded into the upper wiring electrode 6 and theinter-substrate connection wiring electrode 7 coated on the innersurfaces of the upper and lower substrates due to a press force at thetime of forming the gap between the upper and lower substrates so thatthe contact area thereof is increased and hence, the contact resistancebecomes more uniform.

[0063] Further, when the metal particles which are formed by applyingthe metal plating made of gold, nickel or the like around large-diameterplastic particles, the plastic particles are collapsed due to a pressforce at the time of forming the gap between the upper and lowersubstrates so that the contact area thereof is also increased and hence,the contact resistance also becomes more uniform.

[0064] According to this example, the electric contact between the upperwiring electrode 6 and the inter-substrate connection wiring electrode 7disposed between the upper and lower substrates is also enhanced so thatthe irregularities of the resistance value are reduced and anadvantageous effect that the linearity of the resistance value detectioncan be made stable is obtained. Further, the allowance of thedisplacement between the upper wiring electrode 6 and theinter-substrate connection wiring electrode 7 due to an external forceand the return of them to the original position can be realized.

[0065] With the provision of the constitution of the touch panelexplained in the above-mentioned first embodiment, the erroneousoperation of the coordinates inputted through the screen can beprevented so that it becomes possible to provide a screen input typedisplay device which can realize a highly reliable screen inputting.

[0066]FIG. 5 is a developed perspective view for explaining an entireconstitution of the second embodiment of a touch panel which constitutesa screen input type display device of the present invention. In thedrawing, numerals 6A, 6B indicate upper wiring electrodes, numerals 7A,7B indicate inter-substrate connection wiring electrodes formed on theinner surfaces of the lower substrate 3, numeral 80 indicates conductivepressure sensitive adhesive members which electrically connect thewiring electrodes 6A, 6B of the upper substrate 2 and theinter-substrate connection wiring electrodes 7A, 7B at seal portions ofthe upper and lower substrates. Parts having the same numerals withthose shown in FIG. 1 correspond to identical functional parts.

[0067] In this embodiment, an upper resistance film 4 is formed on theentire surface of the inner surface of the upper substrate 2 and theupper wiring electrodes 6A, 6B are formed on the upper resistance film 4in the vicinity of both end portions thereof (left and right sides ofFIG. 5). Pressure sensitive adhesive tapes 15 make the upper and lowersubstrates adhere to each other at portions other than portionscorresponding to the conductive pressure sensitive adhesive members 80.Although the pressure sensitive adhesive tapes 15 are indicated asL-shaped members in FIG. 5, it is preferable to cut a tape-like memberinto strips and to adhere them in view of the easiness of operation.

[0068] Although the lower wiring electrodes 16, the lower wiringelectrode pull-around wirings 18, the inter-substrate connection wiringelectrode pull-around wirings 17 are insulated from the upper resistancefilm 4 by the pressure sensitive adhesive tapes 15, the insulationstructure is not limited to the above and an insulation layers may beseparately provided.

[0069] Since other constitution of this embodiment is identical withthat of the first embodiment which has been explained in conjunctionwith FIG. 1, the repeated explanation of such a constitution is omitted.

[0070]FIG. 6 is a schematic cross-sectional view of an essential parttaken along a line B-B of FIG. 5 which explains the constitution of theseal region in the second embodiment of the present invention in anenlarged form. In this embodiment, the upper wiring electrode 6A formedon the upper resistance film 4 formed on the entire surface of the innersurface of the upper substrate 2 and the inter-substrate connectionwiring electrode 7A formed on the seal region portion of the lowersubstrate 3 are electrically connected by a conductive pressuresensitive adhesive member 80. The above-mentioned wiring electrode 6Aand inter-substrate connection wiring electrode 7A are formed by coatingor printing the silver paste.

[0071] Here, a conductive pressure sensitive adhesive member 80 which isinterposed between the upper wiring electrode 6B and the inter-substrateconnection wiring electrode 7B is formed in the same manner as theconductive pressure sensitive adhesive member 80 which is interposedbetween the upper wiring electrode 6A and the inter-substrate connectionwiring electrode 7A (The same goes for constitutions which will beexplained hereinafter).

[0072]FIG. 7 is a cross-sectional view for schematically explaining thestructure of a first example of the conductive pressure sensitiveadhesive member in the second embodiment of the present invention. Inthis example, the conductive pressure sensitive adhesive member isformed in a taped shape by forming acrylic-based pressure sensitiveadhesive material 80B in which conductive particles 80C are mixed onboth surfaces of the metal foil 80A. As the metal foil 80A, a copperfoil or an aluminum foil may be used or alternatively rubber-basedpressure sensitive adhesive material may be used in place of theacrylic-based pressure sensitive adhesive material.

[0073] Due to the constitution of this embodiment, the electric contactbetween the conductive particles 80C and the upper wiring electrode 6(6A, 6B), the inter-substrate connection wiring electrode 7 (7A, 7B) andthe metal foil 80A is increased, the uniformity of the gap is obtained,and the electric contact of the upper wiring electrode 6 and theinter-substrate connection wiring electrode 7 disposed between the upperand lower substrates is improved so that the irregularities of theresistance values are reduced whereby an advantageous effect that thelinearity of the resistance value detection can be made stable isobtained. Simultaneously, the allowance of the displacement between theupper wiring electrode 6 and the inter-substrate connection wiringelectrode 7 due to the external force and the return of the upper wiringelectrode 6 and the inter-substrate connection wiring electrode 7 to theoriginal position can be obtained as in the case of the above-mentionedrespective examples.

[0074]FIG. 8 is a cross-sectional view for schematically explaining thestructure of a second example of the conductive pressure sensitiveadhesive member in the second embodiment of the present invention. Inthis example, the conductive pressure sensitive adhesive member isformed in a taped shape by applying acrylic-based pressure sensitiveadhesive material 80B in which conductive particles 80D are mixed toboth surfaces of the metal foil 80A. Here, the conductive particles 80Dare formed by applying a metal plating on surfaces of hard plasticparticles which are preferably made of PET. As the conductive particles80D, conductive particles to which the metal plating made of nickel orgold is applied can be used. Alternatively, rubber-based pressuresensitive adhesive material may be used in place of the acrylic-basedpressure sensitive adhesive material.

[0075] Due to the constitution of this example, the electric contactbetween the conductive particles 80D and the upper wiring electrode 6(6A, 6B), the inter-substrate connection wiring electrode 7 (7A, 7B) andthe metal foil 80A is improved. Further, in the case that the conductiveparticles formed by applying a metal plating on surfaces of plasticparticles is used as the conductive particles 80D, when the upper andlower substrates 2, 3 are laminated to each other and a gap is formedbetween both substrates, the collapsing of the plastic particles occursdue to the press pressure at the time of forming the gap.

[0076] Accordingly, the uniformity of the gap is obtained, and theelectric contact of the upper wiring electrode 6 and the inter-substrateconnection wiring electrode 7 disposed between the upper and lowersubstrates is improved so that the irregularities of the resistancevalues are reduced and an advantageous effect that the linearity of theresistance value detection can be made stable is obtained. Further, theallowance of the displacement between the upper wiring electrode 6 andthe inter-substrate connection wiring electrode 7 due to an externalforce and the return of them to the original position can be realized.

[0077] With the provision of the constitution of the touch panelexplained in the above-mentioned second embodiment, the erroneousoperation of the coordinates inputted through the screen can beprevented so that it becomes possible to provide a screen input typedisplay device which can realize a highly reliable screen inputting.

[0078]FIG. 9 is a cross-sectional view for schematically explaining thestructure of a third example of the conductive pressure sensitiveadhesive member in the second embodiment of the present invention. Inthis example, the conductive pressure sensitive adhesive member 80 isformed in a taped shape by forming acrylic-based pressure sensitiveadhesive material 80B in which the conductive particles 80C are mixed onthe upper wiring electrode 6A side of the metal foil 80A and by formingacrylic-based pressure sensitive adhesive material in which conductiveparticles 80D which are formed by applying a metal plating on surfacesof hard plastic particles preferably made of PET on the inter-substrateconnection wiring electrode 7A side of the metal foil 80A. As the metalfoil, a copper foil or an aluminum foil can be used. Alternatively,rubber-based pressure sensitive adhesive material may be used in placeof the acrylic-based pressure sensitive adhesive material.

[0079] With the use of the conductive pressure sensitive adhesive member80 having the structure of this example, when the upper and lowersubstrates 2, 3 are laminated to each other and a gap is formed betweenboth substrates, the collapsing of the plastic particles occurs due tothe press pressure at the time of forming the gap. Accordingly, thecontact area of the conductive particles with the upper wiring electrode6 (6A, 6B), the inter-substrate connection wiring electrode 7(7A, 7B)and the metal foil 80A is increased so that the irregularities of theresistance values are reduced and an advantageous effect that thelinearity of the resistance value detection can be made stable isobtained. Further, the allowance of the displacement between the upperwiring electrode 6 and the inter-substrate connection wiring electrode 7due to an external force and the return of them to the original positioncan be realized as in the case of the previously-mentioned examples.

[0080]FIG. 10 is a schematic cross-sectional view similar to FIG. 6which explains the constitution of an essential part of a thirdembodiment of a touch panel which constitutes a screen input typedisplay device according to the present invention. This embodiment ischaracterized by eliminating the upper wiring electrode 6 which iscoated on the upper resistance film 4 formed on the inner surface of theupper substrate 2 from the constitution explained in conjunction withFIG. 7, FIG. 8 and FIG. 9.

[0081] That is, in this embodiment, the conductive pressure sensitivematerial 80B in which the conductive particles 80C or 80D of theconductive pressure sensitive adhesive member 80 which face the uppersubstrate in an opposed manner are mixed is directly adhered to theupper resist film 4.

[0082] Due to this embodiment, in addition to the above-mentionedadvantageous effects of respective embodiments, a step for forming theupper wiring electrode becomes unnecessary and hence, the reduction ofcost can be achieved.

[0083] With the provision of the constitution of the touch panelexplained in the above-mentioned third embodiment, the erroneousoperation of the coordinates inputted through the screen can beprevented so that it becomes possible to provide a screen input typedisplay device which can realize a highly reliable screen inputting.

[0084]FIG. 11 is a schematic cross-sectional view for explaining theconstitution of a conductive pressure sensitive adhesive member of thefourth embodiment of the touch panel which constitutes the screen inputtype display device of the present invention. In this embodiment, aconductive pressure sensitive adhesive member 80 is formed by embeddinglarge-diameter conductive particles 80E in pressure sensitive adhesivematerial 80B. As the conductive particles 80E, plastic particles whichapply a metal (gold, nickel or the like) plating on surfaces thereof areused.

[0085] These large-diameter conductive particles 8E are provided forcontrolling the gap between the upper and lower substrates. By adheringthe upper and lower substrates using this conductive pressure sensitiveadhesive member 80, the gap between the upper and lower substrates canbe controlled. When the conductive particles which form the plating madeof metal such as nickel or the like on the surfaces of large-diameterplastic particles are used, the plastic particles are collapsed by apress force at the time of forming the gap between the upper and lowersubstrates and hence, the contact area is increased and the contactresistance becomes more uniform.

[0086] In this embodiment also, the electric contact between the upperand lower substrates is enhanced so that an advantageous effect that theirregularities of the resistance values are reduced whereby thelinearity of the resistance value detection can be made stable isobtained. Simultaneously, the allowance of the displacement between theupper wiring electrode and the inter-substrate connection wiringelectrode due to an external force and the return of them to theoriginal position can be realized as in the case of thepreviously-mentioned examples.

[0087] The large-diameter metal particles may be used in place of theconductive particles 80E which are formed by applying a metal plating onsurfaces of large-diameter plastic particles. In this case, the metalparticles are embedded into the upper wiring electrode and theinter-substrate connection wiring electrode coated on the inner surfacesof the upper and lower substrates due to a press force at the time offorming the gap between the upper and lower substrates so that thecontact area thereof is increased and hence, the contact resistancebecomes more uniform.

[0088] In this embodiment also, the electric contact between the upperand lower substrates is enhanced so that an advantageous that theirregularities of the resistance values are reduced whereby thelinearity of the resistance value detection can be made stable can beobtained. Simultaneously, it becomes possible to obtain an advantageouseffect that the mechanical strength of the laminated upper and lowersubstrates can be enhanced.

[0089] With the provision of the constitution of the touch panelexplained in the above-mentioned fourth embodiment, the erroneousoperation of the coordinates inputted through the screen can beprevented so that it becomes possible to provide a screen input typedisplay device which can realize a highly reliable screen inputting.

[0090]FIG. 12 is an explanatory view of fabrication steps of the touchpanel used in the screen input type display device of the presentinvention. In the drawing, numeral 20 indicates a lower substrateprocessing step, numeral 30 indicates an upper substrate processingstep, numeral 40 indicates an assembling step, and numeral 50 indicatesan inspection step.

[0091] In the lower substrate processing step 20, after cleaning areceived glass on which an ITO film has been already formed as a lowerresistance film by a cleaning machine, spacers (dot spacers in thisstep) are printed on the glass by a printing machine. A conductive pastemade of silver (Ag) paste or the like is printed on both ends (see theabove-mentioned embodiments) of the glass substrate so as to forminter-substrate connection wiring, lower wiring electrodes andpull-around wiring.

[0092] Thereafter, an inoperable region forming member (14 in FIG. 19)is printed around an input region. Conductive pressure sensitiveadhesive members are laminated using a tape laminating machine and thenpressure sensitive adhesive tapes 15 are laminated thus obtaining alower substrate.

[0093] In processing an upper substrate, a received PET film providedwith an ITO film as an upper resistance film is cut into a given size bya film cutter and cut films are cleaned and are subjected to anannealing treatment. Thereafter, a conductive paste such as a silverpaste or the like is printed on the film to obtain the upper substrate.Here, with respect to the example as explained in the embodiment shownin FIG. 10 in which the conductive pressure sensitive adhesive membersare directly adhered to the upper substrate this silver paste printingstep is omitted.

[0094] In the assembling step 40, the produced upper and lowersubstrates are laminated to each other by a laminating machine and aresubjected to the pressure sensitive adhesion while setting a given gaptherebetween. After performing the pressure sensitive adhesion, thelaminated substrates are cut into a product size using a cutting machineand, as a final step, an FPC which constitutes a signal output terminalis adhered to the cut piece with pressure so as to complete a touchpanel. The completed touch panel is transported to an inspection stepwhere the completed touch panel is checked with respect to giveninspection items.

[0095] In the above-mentioned embodiments, although the explanation ismade with respect to the case in which the inter-substrate connectionwiring electrodes and the pull-around wiring are formed on the lowersubstrate side, these may be formed on the opposite-side substrate, thatis, the upper substrate side. Further, the electric connection of thesecomponents to the FPC may be performed at the upper substrate side. Inthis case, the pull-around wiring to the FPC and the inter-substratewiring electrodes which connect the lower resistance film to the uppersubstrate may be formed on the upper substrate, and they may beelectrically connected to each other using pressure sensitive tapessimilar to those of the above-mentioned embodiment.

[0096] One embodiment of an entire constitution of a screen input typedisplay device of the present invention which incorporates the touchpanel produced in the above-mentioned manner therein is explained indetail in conjunction with FIG. 13 to FIG. 17.

[0097]FIG. 13 is a cross-sectional view for explaining one embodimentusing a liquid crystal display device as a screen input type displaydevice of the present invention. In this embodiment, an auxiliary lightsource device 200 which includes a light guide body 201 and a linearlamp 202 and a touch panel 100 are mounted on a reflection type liquidcrystal panel 300.

[0098] A reflection layer 302 made of an aluminum thin film, aprotective film 303 made of a reflection prevention film such as SiO2 orthe like and a lower electrode (signal electrode) 304 made of atransparent conductive film such as ITO or the like are formed on aninner surface of a first substrate 301 which constitutes a lowersubstrate of the liquid crystal panel 300.

[0099] Further, on an inner surface of a second substrate 305 whichconstitutes an upper glass substrate, color filters 306 of three colors(R, G, B) which are formed by doping dye or pigment into an organicresin film, a protective film 307 made of organic material whichprevents impurities from being mixed into a liquid crystal layer 309from the color filters 306 and flattens an inner surface of the secondsubstrate 305 and an upper electrode (scanning electrode) 308 made of atransparent conductive film such as ITO or the like are formed.

[0100] Here, grid-like or stripe-like light-shielding films (blackmatrix) are formed among respective colors R, G, B which constitute thecolor filters 306 when necessary and the protective film 307 is formedon the light-shielding films.

[0101] A liquid crystal layer 309 made of a liquid crystal composite isinserted between the first and second substrates 301, 305 and is sealedby seal material 310 made of epoxy resin or the like thus constituting aliquid crystal display panel.

[0102] On a surface of the second substrate 305 of the liquid crystalpanel, a polarizer 312 b, a first phase difference plate 312 c and asecond phase difference plate 312 d are laminated. Between each two ofthe second substrate 305, the polarizer 312 b, the first phasedifference plate 312 c and the second phase difference plate 312 d,adhesive layers 311, 311 a made of an adhesive agent (for example,epoxy-based or acrylic-based adhesive agent), pressure sensitiveadhesive material or the like is formed so as to fixedly securerespective members.

[0103] Here, the adhesive agent means an adhesive agent with which evenwhen two optical films 312 of various kinds which are once laminated arepeeled off, such optical films 312 can be laminated to each other again.By fixing various optical films 312 and the liquid crystal panel usingsuch an adhesive agent, when the optical film 312 and the liquid crystalpanel are fixed erroneously, the optical films 312 and the liquidcrystal panel are reproducible so that the yield of fabrication can beenhanced.

[0104] The reflection layer 302 may preferably have the mirrorreflection characteristics in view of the reflectance. In thisembodiment, an aluminum film is formed by a vapor deposition technique.A multi-layered film may be formed on the surface of the reflectionlayer 302 for enhancing the reflectance. Further, a protective film 303is formed on the reflection layer 302 for the purpose of protecting thereflection layer 302 from erosion and of flattening the surface of thereflection layer 302.

[0105] Here, the reflection layer is not limited to an aluminum film andmay be a metal film made of chromium or silver or a non-metallic film solong as the film has the mirror reflection characteristics.

[0106] Further, the protective film 303 is not limited to the SiO2 filmand may be any insulation film which can protect the reflection layer302. That is, an inorganic film such as a silicon nitride film or thelike, an organic metal film such as an organic titanium film or the likeor an organic film made of polyimide or epoxy resin or the like may beused. Particularly, the organic film made of polyimide or epoxy resin orthe like exhibits an excellent flatness and hence, a lower electrode 304which is formed on the protective film 303 can be easily formed.Further, when the organic metal film such as the organic titanium filmor the like is used as the protective film 303, it becomes possible toform the lower electrode 304 at high temperature so that the wiringresistance of the lower electrode 304 can be decreased.

[0107] Above the liquid crystal panel which mounts the multi-layeredoptical films 312, an illumination device which includes a light guidebody 201 and a light source 202 is disposed as an auxiliary illuminationdevice 200 which is used when the external light is insufficient.

[0108] The light guide plate 201 is made of a transparent resin such asacrylic resin and a print patterning or a surface irregularityprocessing is applied to a viewer side surface (upper surface) of thelight guide plate 201 to make a light L4 of the light source 202irradiated toward the liquid crystal panel side.

[0109] Further, on the auxiliary illumination device 200, a touch panel100 is mounted. In this touch panel 100, when the surface of the touchpanel 100 is pushed with a rod-like body having a sharpened tip such asa nib or a fingertip, the coordinates of a position corresponding to apushed portion is detected and data signals to be transmitted to a host(550 in FIG. 17 which will be explained later) of an informationprocessing device (547 in FIG. 17 which will be also explained later)are outputted.

[0110] The second substrate 305 of the liquid crystal panel 300, thelight guide body 201 of the auxiliary light source device 200 and thetouch panel 100 are fixedly secured to each other by a pressuresensitive adhesive double coated tape (for example, nonwoven fabricimpregnated with a pressure sensitive adhesive agent) or the like.

[0111] With the use of the pressure sensitive adhesive double coatedtape, after the liquid crystal panel 300, the auxiliary light sourcedevice 200 and the touch panel 100 are laminated to each other, it ispossible to peel off them and hence, even when the liquid crystal panel300, the auxiliary illumination device 200 and the touch panel 100 areerroneously fixed, they can be reproduced.

[0112] This auxiliary illumination device 200 is not always necessaryand is unnecessary in an environment which is always bright.

[0113] In this embodiment, the adhesive layer 311 a which is disposedbetween the first phase difference plate 312 c and the second phasedifference plate 312 d is provided with a light diffusion function. Tobe more specific, light diffusion material having a refractive indexdifferent from that of the adhesive agent is mixed in the adhesiveagent. When an epoxy resin-based adhesive agent or an acrylic-basedadhesive agent is used as the adhesive material, transparent organicparticles made of polyethylene, polystyrene, divinylbenzene ortransparent inorganic particles made of silica or the like can be usedas the light diffusion material.

[0114] Here, as the adhesive material, pressure sensitive adhesivematerial having the refractive index different from that of the lightdiffusion material can be used. In this case, even when the first phasedifference plate 312 c and the second phase difference plate 312 d areerroneously laminated to each other, it is possible to reproduce them.

[0115] With the use of the transparent organic particles or inorganicparticles as the light diffusion material, the absorption in the visiblelight region can be reduced and hence, the reflectance and the spectralcharacteristics of the liquid crystal panel can be improved.

[0116] Further, when the organic-based material is used as the adhesiveagent, by using the organic particles as the light diffusion material,the difference of thermal expansion coefficient between them can bedecreased so that the occurrence of cracks in the adhesive layer 311 acan be prevented.

[0117] Although cracks are liable to occur in the adhesive layer bymixing the light diffusion material in the adhesive agent compared tothe case which uses only the adhesive material, by inserting theadhesive layer 311 a containing the light diffusion material thereinbetween the first phase difference plate 312 c and the second phasedifference plate 312 d having the substantially same thermal expansioncoefficient, a problem that cracks occur in the adhesive layer 311 a canbe obviated.

[0118] Subsequently, The display principle of the constitution shown inFIG. 13 is explained. An incident light L1 which is incident on theliquid crystal display device 400 from various directions reaches thereflection layer 302 after passing the touch panel 100, the light guideplate 201 of the auxiliary illumination device 200, the polarizer 312 b,the adhesive layer 311 which is provided for fixing the polarizer 312 bto the first phase difference plate 312 c, the first phase differenceplate 312 c, the adhesive layer 311 a having a light diffusion functionwhich is provided for fixing the first phase difference plate 312 c tothe second phase difference plate 312 d, the second phase differenceplate 312 d, the adhesive layer 311 which is provided for fixing thesecond phase difference plate 312 d to the second substrate 305, thesecond substrate 305, the color filters 306, the upper electrode 308,the liquid crystal layer 309 and a specified pixel electrode (or aspecified signal electrode) 304 a.

[0119] The external light L1 which has reached the reflection layer 302is reflected to become a reflection light L2 and the reflection light L2reaches the adhesive layer 311 a having a light diffusion functionthrough a path inverse to the path of the incident light L1. Thereflection light L2 which has entered the adhesive layer 311 a isscattered in various directions to generate scattering lights L3.

[0120] The direct reflection light L2 and the scattering lights L3irradiated from the adhesive layer 311 a are emitted to the outside ofthe liquid crystal display device 400 after passing the first phasedifference plate 312 c which compensates for the phase differencegenerated when the light passes the liquid crystal layer 309 by makinguse of the birefringence effect, the adhesive layer 311, the polarizer312 b, the light guide plate 201 and the touch panel 100.

[0121] The viewer can recognize the display controlled by the specifiedpixel 304 a by observing the direct reflection light L3 emitted to theoutside of the liquid crystal display device.

[0122]FIG. 14 is a cross-sectional view for explaining other embodimentof the screen input type display device of the present invention. Partsindicated by the same numeral in FIG. 13 corresponds to parts havingidentical functions. In this embodiment, an auxiliary light sourcedevice 200 similar to the device explained in conjunction with FIG. 13is laminated on the liquid crystal panel 300 and a touch panel 100 ismounted on the auxiliary light source device 200 thus constituting ascreen input type liquid crystal display device 400.

[0123] The liquid crystal panel 300 is a thin film transistor (TFT) typeliquid crystal panel which is a typical example of an active matrixtype. A plurality of pixels each of which has a thin film transistorTFT1 and a pixel electrode 304 a are formed on the inside of a firstsubstrate 301 which constitutes the liquid crystal panel 300.

[0124] Each pixel is arranged in a region where two neighboring scanningsignal lines and two neighboring video signal lines cross each other.The thin film transistor TFT1 is constituted of a first semiconductorlayer (channel layer) AS which is formed on the first substrate 301, asecond semiconductor layer (semiconductor layer doped with impurity) r0formed on the first semiconductor layer AS and a source electrode SD1and a drain electrode SD2 formed on the second semiconductor layer r0.Here, although the source electrode SD1 and the drain electrode SD2 arerespectively formed of a multi-layered film made of conductive films r1and r2, the source electrode SD1 and the drain electrode SD2 may beformed of a single-layered film made of only the conductive film r1.

[0125] Although the relationship between the source electrode and thedrain electrode becomes inverse depending on the manner of applying avoltage, that is, the electrode SD2 becomes the source electrode and theelectrode SD1 becomes the drain electrode, the electrode SD1 is set asthe source electrode and the electrode SD2 is set as the drain electrodein a following explanation for facilitating the understanding of theinvention.

[0126] In the drawing, PSV1 indicates an insulation film (protectivefilm) which protects the thin film transistor TFT1, numeral 304 aindicates the pixel electrode, ORI1 and ORI2 respectively indicateorientation films for orienting a liquid crystal layer 309 which isbrought into contact with the first substrate 301 side and a secondsubstrate 305 side, and numeral 308 indicates an upper electrode (commonelectrode).

[0127] BM indicates a light shielding film which is also called a blackmatrix. The light shielding film BM has a function of enhancing thecontrast by shielding light between neighboring pixel electrodes 304 a.Numeral 310 indicates a conductive film which makes the upper electrode308 electrically connected to a terminal (multi-layered metal conductivefilm made of g1, g2, r1, r2 and r3) formed on the first substrate 301.

[0128] In the thin film transistor TFT1, as in the case of aninsulation-gate-type field-effect transistor, when a selective voltageis applied to a gate line voltage GT, the source electrode SD1 and thedrain electrode SD2 are electrically connected and hence, the thin filmtransistor TFT1 functions as a switch.

[0129] The pixel electrode 304 a is connected to the source electrodeSD1, the video signal line is connected to the drain electrode SD2, andthe scanning signal line is connected to the gate electrode GT.Depending on the selective voltage applied to the scanning signal line,the specified pixel electrode 304 a is selected and a gradation voltageapplied to the video signal line is supplied to the specified pixelelectrode 304 a. A CST formed of a conductive film g1 constitutes acapacity electrode and has a function of holding the gradation voltagesupplied to the pixel electrode 304 a by a next selection period.

[0130] This active matrix type liquid crystal panel 300 is provided withthe switching element such as the thin film transistor or the like foreach pixel and hence, a problem that a crosstalk is generated betweendifferent pixels can be obviated and it is unnecessary to suppress thecrosstalk by a special drive such as a voltage equalization methodwhereby the multi-gradation display can be realized. Further, the activematrix type liquid crystal panel 300 has other features including afeature that the contrast is not decreased even when the number ofscanning lines are increased.

[0131] In this embodiment, the pixel electrode 304 a is constituted of areflection metal film made of aluminum, chromium, titanium, tantalum,molybdenum or the like. Further, since the protection film PSV1 isdisposed between the pixel electrode 304 a and the thin film transistorTFT1, even when the pixel electrode 304 a is made large and eventuallyis superposed on the thin film transistor TFT1, the erroneous operationcan be prevented whereby the liquid crystal panel having highreflectance can be realized.

[0132] Further, this liquid crystal panel is not provided with the firstphase difference plate which is used in the liquid crystal panel of aform explained in FIG. 13 and instead is provided with a third phasedifference plate 312 e for improving the visual angle characteristics.This third phase difference plate 312 e is also called a visual angleenlargement film and improves the angle dependency of the displaycharacteristics of the liquid crystal panel by making use of thebirefringence characteristics.

[0133] The third phase difference plate 312 e can be constituted of anorganic resin film made of polycarbonate, polyacrylate, polysulfone orthe like and hence, by using a light diffusion adhesive layer 311 a asan adhesive layer for fixing the third phase difference plate 312 e tothe second phase difference plate 312 d, the occurrence of the cracks inthe light diffusion adhesive layer 311 a can be prevented.

[0134]FIG. 15A to FIG. 15E are views as viewed from five directions forexplaining the outer appearance of a screen input type display deviceaccording to the present invention, wherein FIG. 15A is a front view asviewed from a display surface side, FIG. 15B is an upper side view, FIG.15C is a lower side view, FIG. 15D is a left-side side view, and FIG.15E is a right-side side view.

[0135] In FIG. 15A to FIG. 15E, numeral 318 indicates an upper case(shield case) constituted of a metal plate made of stainless steel,iron, aluminum or the like and numeral 320 indicates a first openingwhich constitutes a display window formed on the upper case 310. Numeral319 indicates a lower case constituted of a metal plate made ofstainless steel, iron, aluminum or the like or plastic such aspolycarbonate, ABS resin or the like.

[0136] Numeral 321 indicates pawls formed on the upper case 318 andnumeral 322 indicates hooks formed on the lower case 319. The upper case318 is connected to the lower case 319 by pressing the lower case 319 tothe upper case with the engagement of the pawls 321 and the hooks 322.

[0137] Numeral 201 indicates a light guide plate made of transparentmaterial such as acrylic resin, glass or the like, numeral 202 indicatesa light source (lamp) such as a fluorescent lamp, a LED or the like.They constitute an auxiliary light source device 200 (here, a frontlight) which illuminates the liquid crystal panel 300 when an externallight is insufficient. Numeral 100 indicates a touch panel for inputtingdata to be transmitted to a host (information processing part) connectedto a liquid crystal display device 400.

[0138] Numeral 312 indicates optical films such as a light diffusionlayer, a polarizer, a phase difference plate and the like which areformed on a display part of the liquid crystal display device 400. Tomake the entire thickness of the liquid crystal display device thin,these optical films are designed such that they are accommodated in aregion of an opening of the upper case 318.

[0139]FIG. 16A to FIG. 16D are cross-sectional views of an essentialpart of FIG. 15A to FIG. 15E, wherein FIG. 16A is a cross-sectional viewtaken along a line A-A of FIG. 15A, FIG. 16B is a cross-sectional viewtaken along a line B-B of FIG. 15B, FIG. 16C is a cross-sectional viewtaken along a line C-C of FIG. 15C, and FIG. 16D is a cross-sectionalview taken along a line D-D of FIG. 15D.

[0140] The liquid crystal panel is fabricated such that the firstsubstrate 301 and the second substrate 305 are laminated to each other,the liquid crystal is injected in a gap formed by such lamination andthereafter an injection opening is sealed by sealing material 331. Anopening 323 is formed in a portion of the upper case 318 whichcorresponds to the sealing material 331 so that even when the sealingmaterial is protruded, the expansion of the size of the contour of theliquid crystal panel can be prevented.

[0141] On the peripheries of the first substrate 301 and the secondsubstrate 305, a printed circuit board (scanning line drive PCB) 330 fordriving scanning lines which mounts a scanning line drive IC chip 328 isarranged. The printed circuit board 330 is connected to the liquidcrystal panel through a flexible printed circuit board 329.

[0142] Further, on the peripheries of the first substrate 301 and thesecond substrate 305, a printed circuit board (signal line drive PCB)333 for driving signal lines which has a flexible printed circuit board329, mounts a signal line drive IC chip 332 and is connected to theliquid crystal panel is arranged.

[0143] Various signals and voltages for display are supplied to thescanning line drive PCB 330 and the signal line drive PCB 333 from anexternal circuit (host) through an interface connector 324. Here,although an interface connector 324 is provided to the scanning linedrive PCB 330, the interface connector 324 may be formed on the signalline drive PCB 333.

[0144] Numeral 326 indicates a spacer for fixing the scanning line drivePCB 330 and numeral 327 indicates a spacer for pressing connectionportions which connect the scanning line drive PCB 330 and the signalline drive PCB 333 to the liquid crystal panel. These spacers areconstituted of insulation resilient material such as rubber or the like.

[0145] Numeral 325 indicates a pressure sensitive adhesive double coatedtape and a non-woven fabric impregnated with epoxy-based adhesive agentcan be used as such a tape 325, for example. With the use of thepressure sensitive adhesive double coated tape 325, the upper case 318is fixed to the liquid crystal panel, the upper case of the liquidcrystal panel is fixed to the light guide plate 201 of the auxiliarylight source device 200, and the light guide plate 201 of the auxiliarylight source device 200 is fixed to the touch panel 100.

[0146] In this manner, by fixing the liquid crystal panel, the auxiliarylight source device 200 and the touch panel 100 using the pressuresensitive adhesive double coated tape 325, the assembling operation canbe simplified and the reproduction after the erroneous assembling isfacilitated so that the fabrication yield can be enhanced.

[0147] An inwardly protruding portion 319 a is formed on the lower case319 which provides an integration of the liquid crystal panel togetherwith the upper case 318. This protruding portion 319 a resiliently holdsthe liquid crystal panel.

[0148]FIG. 17 is an explanatory view of one example of an informationprocessing device which uses the screen input type display device of thepresent invention. This image processing device is also called aso-called “portable information terminal” and is constituted of a bodypart 547 and a display part 548. The body part 547 includes a keyboard549, a host (information processing part) 550 having a microcomputer 551and a battery 552.

[0149] The above-mentioned push input type liquid crystal display device400 is mounted on the display part 548 and characters or devices 558 areinputted on the touch panel exposed at the display part or icons 559displayed on the display part are selected using a pen 556 accommodatedin a pen accommodating part 557.

[0150] Further, an inverter power source 554 is mounted on the displaypart 548 for supplying a lighting power to the auxiliary light sourcedevice through a cable 555.

[0151] Signals and voltages for display from the main part are suppliedto an interface connector 324 of the above-mentioned liquid crystalpanel which constitutes the liquid crystal display device 400 mounted onthe display part 548 through an interface cable 553.

[0152] Further, this information processing device can be connected to aportable telephone 560 through a cable 561 so that communication can beperformed by connecting the information processing device to aninformation communication network such as Internet.

[0153] In this manner, with the use of the screen input type displaydevice of the present invention, the information processing device canbe miniaturized and light-weighted so that the availability of thedevice can be enhanced.

[0154] The shape and the structure of this type of portable informationterminal are not limited to those described in the drawing and theportable information terminals having versatile shapes, structures andfunctions can be considered.

[0155] As has been described heretofore, according to the presentinvention, it becomes possible to provide a highly reliable image inputtype display device having a touch panel which can eliminate theerroneous operation for detection of coordinates by stabilizing thelinearity of the resistance value detection of the resist films.

What is claimed is:
 1. A screen input type display device which arranges a touch panel on a display surface of a display device, the touch panel comprising: a first substrate having a first resistance film, a second substrate having a second resistance film, an inter-substrate connection wiring electrode being formed on the second substrate, and a conductive pressure sensitive adhesive member being disposed between the first resistance film and the inter-substrate connection wiring electrode, the conductive pressure sensitive adhesive member electrically connecting the first resistance film and the inter-substrate connection wiring electrode, and the conductive pressure sensitive adhesive member having pressure sensitive adhesive material in which conductive particles are mixed formed on both surfaces of a metal foil for laminating the first substrate and the second substrate.
 2. A screen input type display device according to claim 1 , wherein the first resistance film and the conductive pressure sensitive adhesive member are directly brought into contact with each other.
 3. A screen input type display device according to claim 1 , wherein a first wiring electrode formed on the first resistance film is interposed between the first resistance film and the conductive pressure sensitive adhesive member.
 4. A screen input type display device according to claim 1 , wherein the metal foil is a copper foil.
 5. A screen input type display device according to claim 1 , wherein the conductive particles are metal particles.
 6. A screen input type display device according to claim 1 , wherein the conductive particles are plastic particles to which a conductive metal plating is applied or glass particles to which a conductive metal plating is applied.
 7. A screen input type display device according to claim 1 , wherein the conductive particles at the first substrate side of the metal foil and the conductive particles at the second substrate side of the metal foil are different in kind from each other.
 8. A screen input type display device according to claim 1 , wherein the first substrate is formed of a soft film member and the second substrate is formed of a hard plate.
 9. A screen input type display device according to claim 1 , wherein one of the first substrate and the second substrate is formed of a soft film member and the other is formed of a hard plate, the conductive particles at the hard plate side of the metal foil are formed of plastic particles to which a conductive metal plating is applied and the conductive particles at the soft film member side of the metal foil are formed of metal particles.
 10. A screen input type display device which arranges a touch panel on a display surface of a display device, the touch panel comprising: a first substrate having a first resistance film, a second substrate having a second resistance film, an inter-substrate connection wiring electrode being formed on the second substrate, and a conductive pressure sensitive adhesive member being disposed between the first resistance film and the inter-substrate connection wiring electrode, the conductive pressure sensitive adhesive member electrically connecting the first resistance film and the inter-substrate connection wiring electrode, and the conductive pressure sensitive adhesive member having pressure sensitive adhesive material in which plastic particles to which a conductive metal plating is applied are mixed for laminating the first substrate and the second substrate.
 11. A screen input type display device according to claim 10 , wherein the first resistance film and the conductive pressure sensitive adhesive member are directly brought into contact with each other.
 12. A screen input type display device according to claim 10 , wherein a first wiring electrode formed on the first resistance film is interposed between the first resistance film and the conductive pressure sensitive adhesive member. 